Plaster-board with key-openings.



G. P. CRUMBAUGH.

- PLASTER BOARD WITH KEY OPENINGS,

APPLICATION FILED MAR. 31. 1914.

orney Patented Apr. 2&2, 1917.

fie yen for i of the usual form of. lath and plaster cov-.

a) EL r fliiihi inihi'idw G'EUJRGE P. CRUMEAUGE, SE SE. LQUIS, MISEKGUPQI, ASSIGNQR GFOHE-HLALFS T? EDWIN' Vi. GROVE, OF ST. LOUIS, IVCCISSUURX.

earners Specification of Letters Patent.

Patenteril'rilpr, 24, 1931*? Application filed March 31, 1914. Serial No. 828,590.

To all whom it may concern:

Be it known that I, GEORGE P; CRUM- BAUGH, a citizen of the United States, residing at St. Louis, in the State of Missouri, have invented new and-useful lmprovements in Plaster-Boards with Key- Openings, of which the following is a specification.

This invention relates to a plaster wall sheathing or plaster board to take the place erings applied to studding, and the primary objectof the same is to provide a backin sheet with a corrugated front sheet appliedthereto and having auxiliary key form-- ing means provided in the corrugations thereof and in some instances between the corrugations so that when the plaster is applied over the corrugated sheet it will not only be positively held by the corrugated surface, but also by the auxiliary key forming means embodied in the structure of the corrugations and thereby provide a more reliable plaster securing covering or wall board. A further object of the invention is to provide a covering for a wall to receive plaster composed of a 'backing sheet and a front corrugated sheet secured by a suitable cement which is keyed in relation to portions of the front corrugated sheet. A still further object of the, invent'on is to provide a'wall covering or board to receive plaster having a front corrugated sheet with key forming means embodied in the structure thereof and to embody in Jconnection with the corrugations as a secoidary feature a plurality of Wood or analogous ribs or strips which are removably mounted in or extend through the corrugations.

With these and other ob ects and advantages in view the invention consists in the construction and arrangement of the several parts which will be more fully herein- Fig. 2 is a transverse vertical section through the wall board or covering as shown by Fig.1.:

Fig. 3 is a View similar to Fig. 1 showing a slight modification in the construction.

Fig. 4 is a transverse vertical section taken through the form of the device as shown by Fig. 3.

The improved wall board comprises essentially a flat backing sheet 5 and a front corrugated sheet 6 secured to the backing sheet by any suitable means, such as pitch or as phalt or any other suitable cementitious material. Thebacking sheet and front corrugated sheet or strips may be suitably treated to render the same water and fireproof and flexible or freely workable material may be used in their construction, but for ordinary purposes it is proposed to use paper of a proper thickness or body. As shown in both constructions illustrated by the drawings, the corrugations are formed with a series of openings 7 arranged at regular intervals therein and made as may be desired and found practicable. lhese openings 7 produce key forming means, or when plaster is applied over the corrugations it is forced into the openings 7 and keys thus produced which are efliciently auxiliary to the major keying of the plaster covering through the medium ofthe corrugations I keying means for saidmaterial to set up a more positive secu'rement of the two sheets relatively to each other. In Figs. 3 and 4 the openings 9 between the corrugations coincide with-openings 10 in the backing sheet or strip 5 and produce additional key openings for the plaster, and by this additional key forming means it will be understood that the use of the openings 8 and 9 and 10 is general and that they are not confinedto any precise position relatively to the corrugations or the valleys between the latter.

The backing and corrugated sheets or strips, 5 and 6 when joined or secured to each other to form the wall covering or board will for most purposes be amply strong or rigid enough to sustain the weight of the plaster covering applied thereto, but as a convenient addition to the improved wall covering or board, reinforcing strips or ribs 11 may be used and pushed into the corrugations to increase the rigidity of the wall covering as a whole. In the use of these reinforcing strips or ribsll it will be understood that they may be disposed at such intervals relatively to the corrugations as may be found necessary, andshifted at will when the covering or board is applied to the studding. In some instances it may benecessary'to strengthen the lower portion of the wall covering or board, and under such conditions a number of the strips or ribs 11 may be disposed in close positions at the lower portion of the covering.

' of parts utilize These reinforcing strips or ribs 11 will be found exceptionally useful when the covering is applied on posts or against supports with intervening spaces in con-- tradistinction to a flat or continuous surface or partitionon which the improvedplaster board or wall covering may also be used without the reinforcing ribs or strips. The reinforcing ribs or strips are also particularly advantageous when the plaster board or covering is applied to ceilings, and in all applications of. the plaster board or covering where the reinforcing ribs or strips are used, said strips or ribs may be shifted as desired to the points where the strongest reinforcement may be required. It will be seenith t the auxiliary key forming means or'openings in the ribs render the use of crosslwires or other analogous wires unnecessar and the structure of the piaster board 0 wall covering is thereby materially redu ed in cost of manufacture as well as being bapable of more expeditious organization by reason of the less number in its construction when completed. Moreover, the openings in the corrugations and in some instances in the spaces or valleys between the corrugations permit keys to be formed relatively to the plaster covering applied over the corrugations in different directions so as to set up a resistance to cracking strain or any tendency to separation of the plaster covering from the corrugations, and in those structures where the openings do not extend through the backing sheet, all of the key devices are confined in engagement with the front or corrugated sheet or strip and waste of the plaster is obviated and at the same time a reliable securement thereof results. It will also be understood that in applying the improved plaster board or Wall covering to supporting means therefor the corrugations will preferably be disposed to extend across in horizontal planes or from one portion of the support to another or all continue in the same direction over the support, whatever the nature of the latter may be. The reinforcing ribs hereinbefore specified and shown by the drawing may be constructed of wood, metal, compressed paper, or any other material or substance that may be applicable for the purpose.

. What is claimed is: v

l. A plaster board embodying a noncorrosiveilight structure comprising a fiat backing sheet and a corrugated sheet fixed to one side thereof and provided with a plurality of hollow corrugations closed at their rear portions by said backing sheet, the corrugations projecting solely from one side of the backing sheet so that the latter may be applied against a support without interference of projections thereon, the corrugated sheet having openings formed through the side portions and apexes of the corrugations thereof, the openings in the apexes belng in alternate relation to the openings in the side portions of the corrugations to avoid weakening the corrugations and to provide a greater plurality of key forming means, openings-also being formed in the bottoms of the valleys between the corrugations.

2. A plaster board comprising a flat backing sheet having a corrugated sheet secured against one side thereof and formed with hollow corrugations projecting solely from one side of the backing sheet, the corrugations having key openings formed in the opposite side portions thereof and in the apexes of thesame, the openings in the .apexes of the corrugations being in alterhollow corrugations projecting solely from one side of the backing sheet and closed at their rear portions by the latter sheet,

the corrugations having openings in the sides thereof and also in the valleys between the corrugations to form keys extending in different directions relatively to a plaster covering adapted to be applied over the corrugated sheet, and solid ribs 7 my BMW presenca of Wm sfizbscribing Wit bloosely and removably inserted in porfizions messes, of the corrugations to reinforce the latter GEQQRGE P. GRUMBAUGH. am; the plaster board at the paints Where Wimesses: 5 tbs said ribs are applied. I T I GEORGE A. BANDOFPH,

In testimony whereof I have hereunto set JACOBF. LANG. 

